In this case, the solution (REF ) takes the form [1]}
\(x(t)=\sin {(\omega t+\delta )}{\Bigg [I_{1}-q(b_3(t)+b_4(t))\Bigg ]}^\frac{-1}{2m},\nonumber \\y(t)=\cos {(\omega t+\delta )}{\Bigg [I_{1}-q(b_3(t)+b_4(t))\Bigg ]}^\frac{1}{2m},\) 
